Evaporatively cooled mini-split air conditioning system

ABSTRACT

In at least one aspect of this disclosure, a refrigeration system includes an evaporatively cooled condenser configured to transfer heat from the refrigeration system to an atmosphere, an air inlet in fluid communication with the condenser, and an evaporative cooling medium disposed between the atmosphere and the condenser such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser. The evaporative cooling can improve system cooling efficiency by 20-50% or even greater in dry climates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 14/200,885, filed Mar. 7, 2014, the entire contents of which are incorporated by reference herein.

BACKGROUND

1. Field

The present disclosure relates to refrigeration systems, more particularly to mini-split air conditioner systems.

2. Description of Related Art

Approximately 87% of homes in the United States have air conditioning. Air conditioning remains the most energy intensive use of electricity for homes that have mechanical space cooling. Also, air conditioning in summer is the largest factor accounting for utility peak electrical generation demand.

Higher efficiency cooling systems are highly desirable for a means to reduce household energy use. Since inverter controlled mini-split air conditioners are both very efficient and in wide use around the world, adaptations of the technology to achieve improved cooling efficiency are useful.

Conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for more efficient refrigeration systems. There also remains a need in the art for such a system that is easy to make and use. The present disclosure provides a solution for this problem.

SUMMARY

In at least one aspect of this disclosure, a refrigeration system includes a condenser configured to transfer heat from the refrigeration system to the surrounding atmosphere, an air inlet in fluid communication with the condenser, and an evaporative cooling medium disposed between the condenser and the air inlet such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow passing into the condenser.

The evaporative cooling medium can include a corrugated cellulose pad. In some embodiments, the evaporative cooling medium can be attached to a frame surrounding the condenser and/or can be about 2 to about 6 inches thick.

The refrigeration system can further include a wetting system configured to wet the evaporative cooling medium. In some embodiments, the wetting system can include a water collection tray configured to collect water from a water source, at least one tube including a water collection tray opening in fluid communication with the water collection tray and an evaporative cooling medium opening configured to provide the water to the evaporative cooling medium, and at least one pump configured to pump water from the water collection tray to the evaporative cooling medium. In at least one embodiment, the refrigerant gas leaving the condenser can be piped to pass through the water collection tray to provide additional refrigerant sub-cooling and hence greater cooling system performance.

The wetting system can further include a water distribution device disposed between the evaporative cooling medium and the evaporative cooling medium opening of the tube, the water distribution device configured to evenly distribute water to the evaporative cooling medium.

The water distribution device can include at least one sponge configured to distribute water via gravity or capillary action to the evaporative cooling medium, at least one water distribution plate comprising a plurality of apertures to distribute water evenly to the sponge and/or a filter disposed above at least one of the water distribution plate or the sponge.

In at least one aspect of this disclosure, an air conditioning unit can include a condenser configured to transfer heat from the air conditioning unit to the surrounding atmosphere, at least one air inlet in fluid communication with the condenser, an evaporative cooling medium disposed between the atmosphere and the air inlet such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser, and a wetting system configured to wet the evaporative cooling medium.

In at least one aspect of this disclosure, an air conditioner efficiency kit includes an evaporative cooling medium configured to attach to an air conditioning unit and cover at least a portion of an air intake of the air conditioning unit, and a wetting system configured to wet the evaporative cooling medium, the wetting system configured to attach to the air conditioning unit to provide water to the evaporative cooling medium.

These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, embodiments thereof will be described in detail herein below with reference to certain figures, wherein:

FIG. 1A is a front exploded, perspective view of an embodiment of a portion of a refrigeration system in accordance with this disclosure;

FIG. 1B is a rear exploded, perspective view of the portion of the refrigeration system of FIG. 1A;

FIG. 1C is a partial, exploded perspective view of a portion of a refrigeration system in accordance with this disclosure;

FIG. 1D is a plan view of a refrigeration system in accordance with this disclosure, shown partially disposed within an enclosed space;

FIG. 2 is a perspective view of an embodiment of a portion of a refrigeration system in accordance with this disclosure;

FIG. 3 is a partial, perspective view of an embodiment of an evaporative medium disposed in a frame on the portion of the refrigeration system of FIG. 2;

FIG. 4 is a partial view of the evaporative medium of FIG. 3, showing an embodiment of a water distribution system in accordance with this disclosure disposed thereon; and

FIG. 5 is a partial, perspective view of a water collection tray fluidly connected to a water distribution system in accordance with this disclosure.

DETAILED DESCRIPTION

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, embodiments of a refrigeration system, and portions thereof, in accordance with this disclosure is shown in FIGS. 1A-5. The systems and methods described herein can be used to increase efficiency of air conditioning or any other suitable purpose.

In at least one aspect of this disclosure, referring to FIGS. 1A-1D, a first portion 100 of a refrigeration system/heat pump can include a housing 101 defining one or more air inlets 103 a, 103 b and at least one air outlets 105. The first portion 100 also includes at least one condenser 117 configured to transfer heat from the refrigeration system (e.g., from a refrigerant flowing within the condenser) to an atmosphere (e.g., outdoor air). The condenser 117 can be any suitable condenser assembly configured to operate in a refrigeration cycle. The air inlets 103 a, 103 b can be in fluid communication with the condenser 117 such that air can be drawn through housing 101 and through condenser 117 in any suitable manner.

The first portion 100 can include one or more evaporative cooling media 107 a, 107 b disposed between the atmosphere and the air inlets 103 a, 103 b such that at least a portion of airflow from the atmosphere passes through the evaporative cooling media 107 a, 107 b to reduce the temperature of the airflow before passing the airflow over the condenser 117. In some embodiments, at least one evaporative cooling medium (e.g., evaporative cooling medium 107 a and or 107 b) can be disposed between the housing 101 and the condenser 117 in any suitable manner such that the housing contains at least a portion of the evaporative cooling medium (e.g., evaporative cooling medium 107 a and/or 107 b).

The evaporative cooling media 107 a, 107 b can include any suitable medium configured to evaporate a liquid (e.g. water) to a gas (e.g. air) flowing therethrough. In some embodiments, the evaporative cooling media 107 a, 107 b can be one or more corrugated cellulose pads. The evaporative cooling media 107 a, 107 b can be of any suitable dimension or thickness, including, but not limited to, about 2 inches to about 6 inches thick. Greater thicknesses provide improved efficiencies as demonstrated in testing. However, it is anticipated that advanced designs may provide greater moisture evaporation surface area in the lowest possible thickness. In embodiments where there are multiple air inlets 103 a, 103 b as shown in the drawings, the different evaporative cooling media 107 a, 107 b may have the same or different thickness and/or material composition.

Referring additionally to FIG. 2, in some embodiments, the evaporative cooling media 107 a, 107 b can be attached to at least one frame (e.g., frames 109 a, 109 b) surrounding the condenser 117 or a portion thereof. The frame (e.g., frames 109 a, 109 b) can be of any suitable size or shape to hold evaporative cooling media 107 a, 107 b to the housing 101 of first portion 100. The frame (e.g., frames 109 a, 109 b) can be of any suitable material, including, but not limited to, plastic, metal, etc.

Additionally referring to FIGS. 3-5, the refrigeration system can further include a wetting system disposed on the first portion 100 and/or over or otherwise in fluid communication with the evaporative medium (e.g., evaporative cooling medium 107 a and/or 107 b) such that the wetting system is configured to wet the evaporative cooling medium. In some embodiments, the wetting system can include a water collection tray 111 configured to collect water from any suitable water source (e.g., rain water, a pressurized water supply, and/or condensate from cooling coils). The wetting system can include at least one tube 115 including a water collection tray opening in fluid communication with the water collection tray 111. The tube 115 can also include at least one evaporative cooling medium opening (see, e.g., end of tube 115 shown in FIG. 4) configured to provide the water to the evaporative cooling medium (e.g., media 107 a, 107 b) and/or a water distribution system as disclosed herein. While the tube 115 is shown as having a single opening, the tube may include a plurality of holes and run across any desired length of the evaporative cooling medium.

In some embodiments, the water collection tray 111 is in direct fluid communication with at least a portion of the evaporative cooling medium (e.g., evaporative cooling medium 107 a and/or 107 b) such that the evaporative cooling medium can soak up water in the water collection tray 111. In some embodiments, the refrigerant gas leaving the condenser can also be piped to pass through the water in the collection tray 111 to provide additional refrigerant sub-cooling and hence greater cooling system performance.

The wetting system can alternatively or additionally include at least one pump 113 configured to pump water from the water collection tray 111 to the evaporative cooling medium (e.g., media 107 a, 107 b). The pump 113 can be any suitable type of fluid pump and may be configured to operate using a low power source. For example, one or more solar panels can be disposed on or near the first portion 100 and can be electrically connected to the pump 113 or a battery to power the pump 113. The pump 113 can also be connected to and/or include a microcontroller for controlling activation of the pump 113 according to any suitable algorithm implemented via any suitable software and/or hardware.

Referring to FIG. 5, in some embodiments, the wetting system can further include at least one water level sensor 127 configured to determine if sufficient water is available to pump to the water distribution device. The water level sensor may alternatively or additionally be configured to allow water from a water source to flow into water collection tray 111 when the water level is below a predetermined amount by controlling the flow of the water supply in any suitable manner. For example, if the water level sensor 127 does not sense a sufficient amount of water in the water collection tray 111, the sensor 127 can be operatively connected to a valve which opens a water flow to the water collection tray 111 and/or to the evaporative cooling medium, thereby filling the tray 111 to a suitable level and/or for a predetermined period of filling time.

In some embodiments, water enters the water collection tray 111 by its introduction onto the top of the evaporative cooling medium (e.g., media 107 a, 107 b) via an unillustrated tube (e.g., a water hose) connected to a suitable water source. In such embodiments, the water can be allowed to work its way through the evaporative cooling medium (e.g., media 107 a, 107 b) and/or the water distribution system disclosed herein. The water can trickle down the evaporative cooling medium (e.g., media 107 a, 107 b) and any excess not evaporated can be collected and/or stored in the tray 111. This set up can be used replace or reduce the need to add source water to the tray 111 directly.

In some embodiments, the wetting system can further include a water distribution device disposed between the evaporative cooling medium (e.g., media 107 a, 107 b) and the evaporative cooling medium opening of the tube 115. The water distribution device is configured to evenly distribute water to the evaporative cooling medium (e.g., media 107 a, 107 b). The water distribution device can be included and/or disposed within frame (e.g., frames 109 a, 109 b) such that it sits above the evaporative cooling medium (e.g., media 107 a, 107 b), however, any other suitable configuration is contemplated.

The water distribution device can include at least one sponge 121 (or any other suitable sponge-like material) configured to distribute water via gravity or capillary action to the evaporative cooling medium (e.g., media 107 a, 107 b). In some embodiments, the water distribution device further includes at least one water distribution plate 123 comprising a plurality of apertures to distribute water evenly to the sponge 121 and/or a filter 125 disposed above at least one of the water distribution plate 123 or the sponge 121. Additionally, multiple filters 125 may be included in the water distribution system (e.g., above and below water distribution plate 123).

In at least one aspect of this disclosure, a refrigeration system can be used as an air conditioning system (e.g., a mini-split air conditioner; see FIG. 1D) which has a first portion 100 and a second portion 200 (e.g., a fan coil unit (FCU)) disposed inside air conditioned space 300. First portion 100 is thermally connected to second portion 200 via refrigerant lines 119. The second portion 200 can include an evaporator coil and a fan configured to draw air over the evaporator coil for drawing heat from the air inside space 300 to the refrigerant flowing within the refrigeration system, thus cooling the air in space 300. A compressor (not shown) can be included in either the first portion 100 or the second portion 200 for compressing the refrigerant upstream of the condenser 117. Also, at least one expansion valve can be included in at least one of the first portion 100, the second portion 200, and/or the refrigerant lines 119 downstream of the condenser 117.

The first portion 100 releases heat into the atmosphere through condenser 117. The colder the outside air, the more efficiently heat is transferred to the atmosphere. In this respect, in the embodiments shown in the drawings, the first portion 100 draws air through the evaporative media 107 a, 107 b and cools the air through evaporation of water into the air. When the air passes through the inlets 103 a, 103 b to the condenser 117, it is of a lower temperature than the atmosphere air allowing for improved heat transfer and higher overall efficiency of the refrigeration system. In experiments by the inventors, average efficiency gains of 21% (in Energy Efficiency Ratio of EER) have been experimentally achieved in Florida's disadvantageous climate. Moreover, efficiency gains of 50% have been demonstrated under peak conditions at a 95 F outdoor temperature. Improvements to efficiency are anticipated to be greater in dryer climates or with evaporative media pads of greater thickness.

In at least one aspect of this disclosure, an air conditioner efficiency kit, e.g., a retrofit kit configured to retro fit onto an air conditioning unit or portion thereof, includes an evaporative cooling medium (e.g., media 107 a, 107 b) configured to attach to an air conditioning unit and cover at least a portion of an air intake (e.g., intakes 103 a, 103 b) of the air conditioning unit, and a wetting system configured to wet the evaporative cooling medium, the wetting system configured to attach to attached to the air conditioning unit to provide water to the evaporative cooling medium (e.g., media 107 a, 107 b). The kit can further include at least one solar panel, battery, and/or any other suitable circuitry, software, hardware, or the like configured to supply power and/or control a pump (e.g., pump 113) of the wetting system. The kit can further include a water distribution system as part of the wetting system as disclosed herein.

In at least one aspect of this disclosure, a method includes evaporating water into air at an inlet of a refrigeration system condenser such that the air cools before reaching the condenser. The method can further include automatically wetting an evaporative medium using a wetting system as disclosed herein.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for a refrigeration system with superior properties including improved efficiency. While the apparatus and methods of the subject disclosure have been shown and described with reference to embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the spirit and scope of the subject disclosure. 

What is claimed is:
 1. A mini-split air conditioner system, comprising: a condenser configured to transfer heat from the refrigeration system to an atmosphere; an air inlet in fluid communication with the condenser; and an evaporative cooling medium disposed between the atmosphere and the condenser such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser.
 2. The mini-split air conditioner of claim 1, wherein the evaporative cooling medium includes a corrugated cellulose pad.
 3. The mini-split air conditioner of claim 1, wherein the evaporative cooling medium is attached to a frame surrounding the condenser.
 4. The mini-split air conditioner of claim 1, wherein the evaporative cooling medium is about 2 to about 6 inches thick.
 5. The mini-split air conditioner of claim 1, further including a wetting system configured to wet the evaporative cooling medium.
 6. The mini-split air conditioner of claim 5, wherein the wetting system includes: a water collection tray configured to collect water from a water source; at least one tube including a water collection tray opening in fluid communication with the water collection tray and an evaporative cooling medium opening configured to provide the water to the evaporative cooling medium; and at least one pump configured to pump water from the water collection tray to the evaporative cooling medium.
 7. The mini-split air conditioner of claim 6, wherein the wetting system further includes a water distribution device disposed between the evaporative cooling medium and the evaporative cooling medium opening of the tube, the water distribution device configured to evenly distribute water to the evaporative cooling medium.
 8. The mini-split air conditioner of claim 7, wherein the water distribution device includes at least one sponge configured to distribute water via gravity or capillary action to the evaporative cooling medium.
 9. The mini-split air conditioner of claim 8, wherein the water distribution device includes at least one water distribution plate comprising a plurality of apertures to distribute water evenly to the sponge.
 10. The mini-split air conditioner of claim 9, wherein the water distribution device further includes a filter disposed above at least one of the water distribution plate or the sponge.
 11. An air conditioning unit, comprising: a condenser configured to transfer heat from the air conditioning unit to an atmosphere; at least one air inlet in fluid communication with the condenser; an evaporative cooling medium disposed between the atmosphere and the air inlet such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser; and a wetting system configured to wet the evaporative cooling medium.
 12. An air conditioner efficiency kit for a mini-split air conditioner, comprising: an evaporative cooling medium configured to attach to an air conditioning unit and cover at least a portion of an air intake of the air conditioning unit; and a wetting system configured to wet the evaporative cooling medium, the wetting system configured to attach to attached to the air conditioning unit to provide water to the evaporative cooling medium.
 13. The kit of claim 12, wherein the wetting system includes: a water collection tray configured to collect water from a water source; at least one tube including a water collection tray opening in fluid communication with the water collection tray and an evaporative cooling medium opening configured to provide the water to the evaporative cooling medium; and at least one pump configured to pump water from the water collection tray to the evaporative cooling medium.
 14. The kit of claim 13, wherein the wetting system further includes a water distribution device disposed between the evaporative cooling medium and the evaporative cooling medium opening of the tube, the water distribution device configured to evenly distribute water to the evaporative cooling medium.
 15. The kit of claim 14, wherein the water distribution device includes at least one sponge configured to distribute water via gravity or capillary action to the evaporative cooling medium.
 16. The kit of claim 15, wherein the water distribution device includes at least one water distribution plate comprising a plurality of apertures to distribute water evenly to the sponge.
 17. The kit of claim 16, wherein the water distribution device further includes a filter disposed above at least one of the water distribution plate or the sponge. 